Compressor



Aug. 10, 1948. A. H. REDDING COMPRESSOR Filed Sept. 27, 1945 INVENTOR HRNOLD H. REDDINQ.

R-V .M

ATTORNEY Patented Aug. 10, 1948 UNl'lED STATES PATENT OF-FlCE COMPRESSOR Arnold. H. Redding, Swarthmore, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application September 27, 1943, Serial No. 503,930 1 Claim. (Cl. 230119) This invention relates to axial-flow compressors or blowers and it has for an object to provide an improved device of the character set forth.

While not limited thereto, the compressor of the present invention is adapted for use in a gas turbine power plant like that disclosed in the copossible so that space is conserved and the horsepower to weight ratio is high.

It is an object of the present invention to provide an improved axial-flow type compressor, particularly adapted for use with a gas turbine power plant of the character mentioned and having good overall efiiciency while of a design to be of minimum weight and occupy a small space within the plant housing.

In general, it has been the practice to provide a row of stationary guide vanes at the inlet of an axial-flow compressor to provide a proper flow pattern of the gas entering the movable blades of the compressor. These guide vanes effect little useful work on the gas, merely serving to direct the gas at a proper angle to the initial row of compressor blades.

It is, therefore, another object of the present invention to provide an improved axial-flow type of compressor which does not require stationary guide vanes at the inlet end thereof, and in which thefirst row of compressor blades effects compression of the gas while providing a proper flow pattern of the gas for the succeeding stages of the compressor.

These and other objects are effected by the invention as will be apparent from the following description and claim taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. l is a longitudinal sectional view of the structure ii.

Fig. 4 is a developed sectional view taken substantially on the line IV-IV of Fig. 1.

The compressor, generally indicated I ll, comprises a substantially cylindrical casing structure II in which is journaled a rotor structure I! defining with the casing structure an annular flow passage l3 extending axially of the compressor. It will be understood that the present compressor may be incorporated in a gas turbine power plant of the type shown in the aforesaid application, in which case the casing structure II corresponds to the forward portion of the power plant casing.

The rotor I2 is supported by means of bearings, one of which is shown at it, carried by the casing The hearing it is connected to the casing structure by means of circumferentiallyspaced radial struts, one of which is shown at l5, of streamline section, and fixed at their inner ends to the bearing housing l8 and at their outer ends to the casing structure. A fairing cone ll carried by the bearing hub together with the outwardly-fiared inlet surface I8 of the casing structure guides the air into the compressor with minimum turbulence.

Except for the initial stage, the compressor is of the axial-flow type and comprises alternate rows of stationary blades it, carried by the casing structure II and rotor blades 2| carried by the hub structure II. The blades are secured to their respective supporting structures in any satisfactory manner suitable-for operating the rotor at high speeds. Except for the initial row 22 of rotor blades, which will be described in detail later, the rotor and stationary blades are arranged in conventional manner and any desired number of stages may be provided to give the desired compression ratio. One or more rows of fixed guide vanes 23 in the passage immediately following the last row of blades 2i serve to straighten the stream of air so that it flows axially of the compressor.

As mentioned, it has been the practice to provide stationary guide vanes at the inlet of an axial-flow compressor so that the gas entering the compressor enters the first row of rotary blades at the proper angle or, in other words, is traveling in a proper flow pattern. Since space is often at a premium and particularly in a gas turbine power further compression is emciently obtained by the succeeding axial-flow stages oi the compressor. This arrangement reduces the overall length of the compressor and also reduces the number of stages required to eiiect a given compression ratio at the gas.

This result is accomplished by employing an initialrow of rotor blades 22 which move in a blade passage '25 that directs the gas both axially and radial-1y outwardly therealong. To this end,

the forward portion 28 of the rotor structure and the inner wall 21 of the casing structure are shaped to provide a blade passage 2S substantially ogee section and oi increasing mean diameter in the direction of flow. as shown particularly in Figs. 1 and 3. Gas to be compressed enters the compressor substantially axially and is moved radially outward and rearward oi the compressor, leaving the passage 2| substantially; axially.

The ogee-shaped forward end 20 or the rotor is provided with a plurality oi blades 22 arranged in the manner shown in Figs. 2, 3 and 4, which extend for the length 01 the blade passage. 25.1 These blades are oi airfoil section and extend substantially helically about the rotor. The plane of rotation sections or the blades extend radially outward from the axis of the rotor. The blade passage 25 merges smoothly into the blade passage of the axial-now stages of the compresamto reduce turbulence and provide substantially guide vanes which cause the entering air to swirl in the direction of rotation of the blades 22. This swirling is obtained by forming the struts II as uide vanes to direct the entering air at an angle to the axis 01 the compressor and into the passages between the moving blades 22.

While the invention. has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claim.

, and movable blades in the flow passage and carstraight-through flow 0! the gas through the com- Pres-sol.

The blade passages-1| and" are 01' constantly decreasing flow area, so that compression is eiieoted continuously throughout the compressor. By employing a blade passage II and compressor blades 22, substantial compression or the gas is obtained in this initial stage which, at the same time, serves to direct the gas in a proper flow pattern i'or further compressionin the succeeding stages oi the compressor. The initial stage of the compressor, therefore, iunctions not only as guide means for directing the gas into the compressor but also as a semi-centrifugal and axial-flow stage for effecting compression oi the gas.

It' is usually unnecessary to employ inlet guide vanes with the compressor 01 the present invention. However, in certain instances. it may be desirable to have such vanes immediately ahead of the initial row of rotor blades 22. For exampic, inlet guide vanes may be provided it the velocity oi the air entering the compressor relative to the velocity of the moving blades 22 is of superacoustic value resulting in compression shock losses. These losses can be avoided by mean oi ried by said casing structure and said rotor, respectively, the first rowioi blades at the inlet of said compressor being fixed to said rotor, the portion of said passage across which said first row of blades extends being of increasing mean diameter in the direction of flow through said compressor, the remainder of said flow passage extending substantially parallel to the axis oi said comprssor and merging smoothly with the said portion of said passage.

ARNOLD H. BEDDING.

REFERENCES CITED STATES PATENTS Number Name Date 859,938 Gow July 18, 1907 901,228 Collier Oct. 13, 1908 1,497,408 Seeiig June 10, 1924 1,529,925 Say -s Mar. 17, 1925 1,797,455 Vose Mar. 24, 1931 2,168,728 Whittle Aug. 8, 1939 2,216,731 Birmann Oct. 8, 1940 2,274,743 Rosskopi Mar. 3, 1942 2,292,288 Pescara Aug. 4, 1942 2,321,276 DeBoit June 8, 1943 FOREIGN PATENTS Number Country Date 3,740 Great Britain Feb. 14, 1911 12,886 Great Britain Oct. 27, 1885 505,078 Great Britain May 2, i939 

